RFID systems are becoming ubiquitous in everyday life. An RFID system contains two basic elements: a tag unit and an interrogator unit. The tag unit typically comprises an IC and an antenna. The IC comprises memory and processing circuitry. The interrogator unit contains an RF transceiver, processing circuitry, and an antenna. Power to the tag IC may be provided by the interrogator unit, so the tag unit need not contain a power storage system such as a battery. A tag unit that does not contain a power storage system is referred to as a passive tag unit. The interrogator portion may generate a signal that activates any tag unit within reach of the signal. When activated, any tag unit within signal reach transmits any data stored on the memory to the interrogator unit.
In many contexts, the data stored by a tag unit is not confidential. However, in other contexts, the stored data is confidential, and it is desirable to limit access to the data stored on a tag unit. The present invention relates to RFID systems and methods designed to limit access to data stored on a tag unit.
The present invention is of particular significance in the context of a button assembly that stores personal information such as telephone numbers, addresses, and the like. The present invention will thus be described herein in the context of RFID systems and methods that allow personal data to be transmitted from a button assembly to an electronic device such as a telephone or computer for storage and/or further processing. However, the principles of the present invention may have broader application, and the principles of the present invention should be determined by the claims appended hereto and not the following detailed description of the invention.